Diamond bench stone



FIG. 1 is a top perspective view of the ornamental design for diamond bench stone of the invention;

FIG. 2 is a top plan view of the ornamental design for diamond bench stone of FIG. 1;

FIG. 3 is a side elevation view of the ornamental design for diamond bench stone of FIG. 1;

FIG. 4 is an end elevational view of the ornamental design for diamond bench stone of FIG. 1, with the opposite end being the mirror image of FIG. 4; and,

FIG. 5 is a bottom plan view of the ornamental design for diamond bench stone of FIG. 1. 

The ornamental design for a diamond bench stone, as shown and described. 